Well, the vast majority of them are paid pieces -- I haven't checked where we're at for this month but usually ~99.5% of all mail volume is paid (not trials).

As for getting all those postcards, I need to find some way to figure out who's behind them. :)

FWIW, my goal is to see if I can get some customers that would be willing to pay some sort of fee while I ramp up the hardware to actually deliver that sort of service.